The invention relates to a separating device for plates which are arranged at a distance from one another and onto which at least one continuous strip composed of a dry resist layer has been laminated.
Published European Patent Applications Nos. 0,040,842, 0,040,843 and 0,041,642 make known laminating processes in which a substrate or a layer support is laminated with a dry resist on both sides by means of applied pressure. The dry resist to be applied to each side of the layer support to be laminated, for example, a printed circuit board is drawn off from a supply roll and fed to a pair of laminating rollers. Two dry resist films with the layer support located between them run through the nip of the rollers. Before lamination, a thin liquid layer is coated onto the surface of the layer support or printed circuit board and forms an intermediate layer between the surface of the printed circuit board and each respective dry resist film during the laminating operation. The thin liquid layer is removed from the surface of the printed circuit board during lamination by being absorbed into the dry resist film. After lamination, the layer support is provided on both sides with a dry resist layer, so that both sides of the layer support, usually a printed circuit board or printing plate, can be exposed and developed.
U.S. Pat. No. 4,214,936 teaches a laminating process in which horizontally transported plates are moved continuously forward, are contact-heated, and are laminated on both sides. As soon as a sensor detects the trailing edge of the preheated plate, shortly before it enters the nip between the laminating rollers, the rollers are stopped after a certain delay time. This makes it possible for the trailing edge of the plate to pass through the laminating nip. As soon as the leading edge of the following plate is detected, the laminating rollers start to rotate once again, and the plate entering the nip is laminated. This operation is repeated for each new plate, and a uniform distance is therefore maintained between the individual laminated plates after the nip. At the same time, a continuous strip is obtained. This is composed of two dry resist layers, between which the plates are included at an equal distance from one another. The connecting length of the resist layers between two plates can amount, for example, up to 18 mm. A disadvantage here is that separating the plates from one another requires two cutting operations, first to cut off the connecting piece composed of the dry resist along the trailing edge of the front plate and subsequently to cut along the leading edge of the rear plate. Often, even three cutting operations are required, since, during the first cut, only the connecting piece between two plates is initially severed, and only subsequently is the individual plate processed by cutting off the dry resist layer flush with the plate edge that projects beyond the leading or trailing edge. This is done as late as during the finishing of the individual plate.